# Reliability

Source: https://joinsimplesms.com/changelog/2026-10-01-reliability
Index: https://joinsimplesms.com/llms.txt

October 1, 2026

- **Automatic carrier retries**: temporary carrier failures no longer fail a
  send. `POST /v1/messages` answers `202` with the message `queued` and we
  retry it after 30s, 2m and 10m. New message fields: `attempts`,
  `next_attempt_at`. A message is never submitted twice.
- **Missing delivery reports**: a sent message with no delivery report after
  72 hours is marked `receipt_status: "missing"`. Its status stays `sent`.
- **Idempotency-Key** on `POST /v1/verify` and `POST /v1/numbers`. Failed
  requests now release their key.
- **Webhook delivery log**: status code, latency, attempt and the first 2 KB of
  your endpoint's response for every attempt, in the console and at
  `GET /v1/webhooks/deliveries`. `GET /v1/webhooks` lists endpoints.
- **Replay to one endpoint**: `POST /v1/events/{id}/replay`, and per-row
  Replay in the console.
- **Undelivered events**: events whose retries ran out are kept for 30 days
  with one-click replay, instead of being dropped.
- **[Status page](/status)** (and `/status.json`) for the API, sending,
  inbound and webhooks.